/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: RealType.java,v 1.2.4.1 2005/09/05 11:28:45 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.DLOAD;
import com.sun.org.apache.bcel.internal.generic.DSTORE;
import com.sun.org.apache.bcel.internal.generic.GOTO;
import com.sun.org.apache.bcel.internal.generic.IFEQ;
import com.sun.org.apache.bcel.internal.generic.IFNE;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.InstructionConstants;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.NEW;
import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
public final class RealType extends NumberType {

  protected RealType() {
  }

  public String toString() {
    return "real";
  }

  public boolean identicalTo(Type other) {
    return this == other;
  }

  public String toSignature() {
    return "D";
  }

  public com.sun.org.apache.bcel.internal.generic.Type toJCType() {
    return com.sun.org.apache.bcel.internal.generic.Type.DOUBLE;
  }

  /**
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#distanceTo
   */
  public int distanceTo(Type type) {
    if (type == this) {
      return 0;
    } else if (type == Type.Int) {
      return 1;
    } else {
      return Integer.MAX_VALUE;
    }
  }

  /**
   * Translates a real into an object of internal type <code>type</code>. The
   * translation to int is undefined since reals are never converted to ints.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Type type) {
    if (type == Type.String) {
      translateTo(classGen, methodGen, (StringType) type);
    } else if (type == Type.Boolean) {
      translateTo(classGen, methodGen, (BooleanType) type);
    } else if (type == Type.Reference) {
      translateTo(classGen, methodGen, (ReferenceType) type);
    } else if (type == Type.Int) {
      translateTo(classGen, methodGen, (IntType) type);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), type.toString());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Expects a real on the stack and pushes its string value by calling
   * <code>Double.toString(double d)</code>.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      StringType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,
        "realToString",
        "(D)" + STRING_SIG)));
  }

  /**
   * Expects a real on the stack and pushes a 0 if that number is 0.0 and
   * a 1 otherwise.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      BooleanType type) {
    final InstructionList il = methodGen.getInstructionList();
    FlowList falsel = translateToDesynthesized(classGen, methodGen, type);
    il.append(ICONST_1);
    final BranchHandle truec = il.append(new GOTO(null));
    falsel.backPatch(il.append(ICONST_0));
    truec.setTarget(il.append(NOP));
  }

  /**
   * Expects a real on the stack and pushes a truncated integer value
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      IntType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,
        "realToInt", "(D)I")));
  }

  /**
   * Translates a real into a non-synthesized boolean. It does not push a
   * 0 or a 1 but instead returns branchhandle list to be appended to the
   * false list. A NaN must be converted to "false".
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized
   */
  public FlowList translateToDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen,
      BooleanType type) {
    LocalVariableGen local;
    final FlowList flowlist = new FlowList();
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Store real into a local variable
    il.append(DUP2);
    local = methodGen.addLocalVariable("real_to_boolean_tmp",
        com.sun.org.apache.bcel.internal.generic.Type.DOUBLE,
        null, null);
    local.setStart(il.append(new DSTORE(local.getIndex())));

    // Compare it to 0.0
    il.append(DCONST_0);
    il.append(DCMPG);
    flowlist.add(il.append(new IFEQ(null)));

    //!!! call isNaN
    // Compare it to itself to see if NaN
    il.append(new DLOAD(local.getIndex()));
    local.setEnd(il.append(new DLOAD(local.getIndex())));
    il.append(DCMPG);
    flowlist.add(il.append(new IFNE(null)));        // NaN != NaN
    return flowlist;
  }

  /**
   * Expects a double on the stack and pushes a boxed double. Boxed
   * double are represented by an instance of <code>java.lang.Double</code>.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      ReferenceType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new NEW(cpg.addClass(DOUBLE_CLASS)));
    il.append(DUP_X2);
    il.append(DUP_X2);
    il.append(POP);
    il.append(new INVOKESPECIAL(cpg.addMethodref(DOUBLE_CLASS,
        "<init>", "(D)V")));
  }

  /**
   * Translates a real into the Java type denoted by <code>clazz</code>.
   * Expects a real on the stack and pushes a number of the appropriate
   * type after coercion.
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      final Class clazz) {
    final InstructionList il = methodGen.getInstructionList();
    if (clazz == Character.TYPE) {
      il.append(D2I);
      il.append(I2C);
    } else if (clazz == Byte.TYPE) {
      il.append(D2I);
      il.append(I2B);
    } else if (clazz == Short.TYPE) {
      il.append(D2I);
      il.append(I2S);
    } else if (clazz == Integer.TYPE) {
      il.append(D2I);
    } else if (clazz == Long.TYPE) {
      il.append(D2L);
    } else if (clazz == Float.TYPE) {
      il.append(D2F);
    } else if (clazz == Double.TYPE) {
      il.append(NOP);
    }
    // Is Double <: clazz? I.e. clazz in { Double, Number, Object }
    else if (clazz.isAssignableFrom(java.lang.Double.class)) {
      translateTo(classGen, methodGen, Type.Reference);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), clazz.getName());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Translates an external (primitive) Java type into a real. Expects a java
   * object on the stack and pushes a real (i.e., a double).
   */
  public void translateFrom(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    InstructionList il = methodGen.getInstructionList();

    if (clazz == Character.TYPE || clazz == Byte.TYPE ||
        clazz == Short.TYPE || clazz == Integer.TYPE) {
      il.append(I2D);
    } else if (clazz == Long.TYPE) {
      il.append(L2D);
    } else if (clazz == Float.TYPE) {
      il.append(F2D);
    } else if (clazz == Double.TYPE) {
      il.append(NOP);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), clazz.getName());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Translates an object of this type to its boxed representation.
   */
  public void translateBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    translateTo(classGen, methodGen, Type.Reference);
  }

  /**
   * Translates an object of this type to its unboxed representation.
   */
  public void translateUnBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new CHECKCAST(cpg.addClass(DOUBLE_CLASS)));
    il.append(new INVOKEVIRTUAL(cpg.addMethodref(DOUBLE_CLASS,
        DOUBLE_VALUE,
        DOUBLE_VALUE_SIG)));
  }

  public Instruction ADD() {
    return InstructionConstants.DADD;
  }

  public Instruction SUB() {
    return InstructionConstants.DSUB;
  }

  public Instruction MUL() {
    return InstructionConstants.DMUL;
  }

  public Instruction DIV() {
    return InstructionConstants.DDIV;
  }

  public Instruction REM() {
    return InstructionConstants.DREM;
  }

  public Instruction NEG() {
    return InstructionConstants.DNEG;
  }

  public Instruction LOAD(int slot) {
    return new DLOAD(slot);
  }

  public Instruction STORE(int slot) {
    return new DSTORE(slot);
  }

  public Instruction POP() {
    return POP2;
  }

  public Instruction CMP(boolean less) {
    return less ? InstructionConstants.DCMPG : InstructionConstants.DCMPL;
  }

  public Instruction DUP() {
    return DUP2;
  }
}
